<!DOCTYPE html>
<html lang="zh">//

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>DOM 1</title>
    <style>
        .red {
            background: red;
        }
    </style>
</head>

<body>
    示例
    <div>
        <div id="test">
            <p class="red">段落标签1</p>
        </div>
        <div id="test2">
            <p class="red">段落标签2</p>
        </div>
    </div>
    <div id="test3">
        <p class="red">段落标签3</p>
    </div>
    <script src='dom.js'></script>
    <script src='main.js'></script>
</body>

</html>